Process of making dialkyl barbituric acid.



I this commie-F, Ascfi i'FFENBURG, GERMANY, A s sreNon rrd'Tii FIRM or Manon, or

- IDAI ZMS IADQGERMANY -j 1 nlses sos,

; To all whom it may concern: Be itknown that LMAX CONRAD ject of the Emperor of Germany, residing at;

Aschaifenburg, in theEmpire of Germany, have invented certain new and useful Imj provement'sin, the Processes of Manufactur-' rnoc 'usis 'oF'MmNG DIALKYL imnnITUnIc new, f a

, a subng 'Dialkyl 'Malonylamid Compoundsyandv "Dialkyl Barbituric AcidsTherefrom, ofwhich the following is a description."

' 'nvention relates" to themanufacture' --of dialkyl-mal onylamid compounds and dialkyl barbituricacids therefrom, and it consists oicertainnoveljprocesses particularly point- 7 'ed out in the concluding claims.

According to experiments made by'Emil;

- Fisher and AlfredDilthey (Berlin'Reports 35 (1902, p age 844=) the dialkylmalonamids and the dialkylmalonamin acid ester can not i I a practically be obtained from 'dialkylmalonauthorities the only way to-accomplish the, result sought is by means ofthe acidichlorids.

l -consists in moderately heatin the cyandiaL- centrated acids. These dialkylmalonamid-- compounds can be converted in the same acid esters and. also that the ammonium salts of the dialkylmalonacids can not be converted into amids. According to. theabove I have discovered, however, a convenient and smooth method of manufacturing dialkylmalonylamidcompounds. This method.

kylacet amids, the cyandia ylacetylurea, and the cyandialkylaceticester, with conmanner as the "dialkylmalonacidester with u rea,guanidin or thiourea into dialkydbarbituric-acids, under the action of the same 'con-' 'dens'ing means, viz. the alcoholates of alkali or earthy metals, the metals the amide thereof.

I will now describe the manner in which I at present prefer to 1practice my. invention, giving, byway of i1 ustration, a number of examples thereof, but it will be understood themselves or that various modifications and changes ,both

, my claim.

' as to materials and treatment, may be made withoutde arting-from the spirit of my; inventionan withoutexceeding the scope of First examplel lfone part of the cyahdiin the water bath forone hour'Wi-th 5 to 10 parts of'concentrated sulfuric acid, to. which are added referably one or twogp arts of water, and if then the solution is poured out into the water, diethylmalonylamid is separated incrystals. This may be easily pun specificationiof Letters lfatent Application filed N overnber 8, 1904.: Serial m, 231,871.

vfied by dissolvingit I v be s'ubl-imated and .gme'lts jati229f(uncorr.). 1-

Second exam} le'.-* *I'r 1' the some manner;--' from the cyandipropyl acetamid,which melts at 153, the dipropylmalonamid, which'melts aimeyser; It'can at 214, is obtained.-

Third example.+The amid, which-melts at 165, produces, under 'the' same conditions, 7 amid,- which melts at 197. 1

I Fourth exampler-f-From" the-- 7 9 and can be easilyjdissolved, especially with warmth; in ether, spirit,,-acet1c: ether- 'and benzol.

etc. .(uncorri). Iriorder to obtain diethylbarbituricac'id therefrom; gm of sodium are dissolve in 4 liters of'absolutealcohol and to this hotsolution 200 ams of urea and 470 the dlben'zylmalonyl-j I w .,e5 ,e i fl y acetice'sten'the diethylmalonaminacid ester v.

is-obtained in colorless prisins, which melt at The R in the last formula 1 means an alkyl; group such as methyl, ethyl,

' heated'for 'severalhours in thewater bath and the alnohol is then removed by-distillwtion. 'The'solid residue is dissolved-in water and-is decomposed with'aceticacid or hydrochloric 'acid. In this way 210 ams of di ethylbarbituric acid are obtaine a Fifth example.From cyandiprop'ylacetic ester, the dipropylmalonaminacideste'r' isob- "tained ofthe melting point'91 (uncorr.').-v If this ester is treated (in the manner described inthe fourth example) with urea and sodium alcoholate, dipropylbarbituric acid is ob: tained of the melting point 145 (corn).

Sixth example.-From an; alcoholic solution of 60 grams of-sodium, 200 grams of thiourea and 470. grams. of diethylmalon-' aminacidester, with the same treatment, 350' grams of diethylmalonylthiourea are obtained; Thesame melts at 175 C. and "can be easily converted into .diethylbarbituric acid by oxidizing means, or by means of Inetallic oxid, as lead-oxidh Seventh example. A solution of 120 grams of sodium, 240 grams of guandinhyon-aminacidester furnishes under the-same. conditions 250 grams of diethyl-malonygguanidin. This crystallizes in colorless nee es,

drochlorate and 470- grams of diethylmaL 'which decompose at temperatures of over 15 The-ester boils toalarge extent at 263 so grams of ester are a ded. -The mixture is 300 C. without melting. The compound can be dissolved in diluted acids and in excessof ammonia with warmth. By being heated, diluted acids it is converted, while sepae rating ammonia, into. dialkylbarbituric' acids.

is separated when water is added, which prodnot can be easily purified by shaking it with diluted ammonia and dissolving it in hot water. It melts at 199 Thespecific process hereinabove described employingthiourea while generically claimed herein-is-specifically the subject of a separate ap lication, No. 326038 filed July 13, 1906. aving-thus full described my invention, what I claim and esire to secure by Letters Patent,v is t v 1. The processofmanufacturing a dia1kyl-. barbituric acid which consists in-first treating-a cy'andialkylacetic compound. with a concentrated acid, thencondensing the resuiting dialkylmalonylamid com mind with derivative of urea to a dialkylbar ituric acid compound and then converting the latter into a dialkylbarbituric acid.

2. In the process of manufacturing dialkylbarbituric acid the ste which consists in converting acyandialky acetic compound to a dialkylmalonylamid compound by treating with a concentrated acid.

3. In'the process of manufacturing dialkylbarbituric acid the step which consists in converting cyandiethyl acetic ester to diethylmalonamin acid ester by treating with concentrated suliuric acid.

v 4. In the process of manufacturing dialkylbarbituric acid the step which consists in condensing a dialkylmalonylamid com ound with a derivative of urea to a'dialkyl arbituric acid compound and then converting. the

latter into a dlalkylbarbituric acid.

5. In the process of manufacturing'dialkylbarbituric acid the step which consists in condensing diethylrnalonaminacid ester with guanidin to imino-diethylbarbituric acid and then converting the latter into diethylbarbis turic acid by saponification.

In testimony whereof I hereunto sign my name to this specification in the presence of two subscribing witnesses,

MAX CONRAD.

Witnesses JEAN GRUND, CARL GRUNDi 

